2020 · コアルール（プレイに必要な最小限）

24XX System Reference Document

A rules framework for fast, narrative-focused tabletop roleplaying in any setting. Players describe their actions and use the highest result from a roll of polyhedral dice to resolve challenges, with emphasis on fictional positioning rather than detailed procedures or arithmetic. The system supports science-fiction adventures and can be adapted for other genres, settings, and custom games.